VSE: How to Reuse an Animation or how to Create an Animation Template?
Consider


Change Data Files ... a single button in the VSE Panel
Copy and Paste from the Graph Editor Window


Additional


Archive your software by Duplicating the file or entire Scene to Duplicate all VSE Strips.  
Duplicating the Strips in the Particular Scene to test new animations.
A Python Script solution by searching BSE or the internet in general. Obtaining a new Python Script written by someone or you.  Your expertise with Python will be a factor in determining the cost of this.






A Python Script can handle this situation.  The cost could be searching the internet or someone writing it.  You might be that someone.
Sometimes a manual solution may be more time cost or other cost effective depending on arrangement and quantity of data.  If you get lucky.  Probably more people on the BSE site are familiar with Copy and Paste rather than writing a Python Script.

Please know keyframe data can be copied and pasted from the Graph Editor Window.



Copy and Paste from the Menu or use the indicated standard keystrokes.  Image Above.

You might also have a manual copy and paste solution depending on your data quantity and the time cost or other cost of getting a Python Script.  Just like spreadsheet data or text data has a copy and paste with a cursor ... the Blender User may copy points of the one data graph (A) and paste them to a certain target data graph (B) with the graph timeline frame cursor.

Lets imagine an optimistic hypothetical situation. Suppose your Blender Scene situation has 3 independent video strips in a set named [A] in VSE each with 88 transparency keyframes each and 3 dependent video strips in a set named [B]. Next the scene is duplicated and [A] has been given a new animation by you.  Next you may only need to copy and paste actions 3 times to give [B] a new animation.  In this scenario you did [not] manually duplicate the work of thinking about the 88 keyframes individually.